/*
 * ProGuard -- shrinking, optimization, obfuscation, and preverification of Java bytecode.
 *
 * Copyright (c) 2002-2018 GuardSquare NV
 *
 * This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public
 * License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later
 * version.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied
 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along with this program; if not, write to the Free
 * Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */
package proguard.optimize.info;

import proguard.classfile.*;
import proguard.classfile.attribute.CodeAttribute;
import proguard.classfile.constant.*;
import proguard.classfile.constant.visitor.ConstantVisitor;
import proguard.classfile.instruction.*;
import proguard.classfile.instruction.visitor.InstructionVisitor;
import proguard.classfile.util.SimplifiedVisitor;
import proguard.classfile.visitor.MemberVisitor;
import proguard.optimize.OptimizationInfoMemberFilter;

/**
 * This InstructionVisitor counts the number of times methods are invoked from the instructions that are visited.
 *
 * @author Eric Lafortune
 */
public class MethodInvocationMarker extends SimplifiedVisitor
    implements InstructionVisitor, ConstantVisitor, MemberVisitor {
    private final OptimizationInfoMemberFilter filteredMethodMarker = new OptimizationInfoMemberFilter(this);

    // Implementations for InstructionVisitor.

    public void visitAnyInstruction(Clazz clazz, Method method, CodeAttribute codeAttribute, int offset,
        Instruction instruction) {}

    public void visitConstantInstruction(Clazz clazz, Method method, CodeAttribute codeAttribute, int offset,
        ConstantInstruction constantInstruction) {
        clazz.constantPoolEntryAccept(constantInstruction.constantIndex, this);
    }

    // Implementations for ConstantVisitor.

    public void visitAnyConstant(Clazz clazz, Constant constant) {}

    public void visitStringConstant(Clazz clazz, StringConstant stringConstant) {
        // Mark the referenced method, if any.
        stringConstant.referencedMemberAccept(filteredMethodMarker);
    }

    public void visitAnyMethodrefConstant(Clazz clazz, RefConstant refConstant) {
        // Mark the referenced method.
        refConstant.referencedMemberAccept(filteredMethodMarker);
    }

    // Implementations for MemberVisitor.

    public void visitAnyMember(Clazz Clazz, Member member) {}

    public void visitProgramMethod(ProgramClass programClass, ProgramMethod programMethod) {
        incrementInvocationCount(programMethod);
    }

    // Small utility methods.

    private static void incrementInvocationCount(Method method) {
        ProgramMethodOptimizationInfo.getProgramMethodOptimizationInfo(method).incrementInvocationCount();
    }

    /**
     * Returns the number of times the given method was invoked by the instructions that were visited.
     */
    public static int getInvocationCount(Method method) {
        return MethodOptimizationInfo.getMethodOptimizationInfo(method).getInvocationCount();
    }
}
